Font families can be divided into two groups: serif and san serif. A san serif font does not include the small lines at the end of characters, while a serif font does include these small lines. When choosing which kind you prefer, remember that studies have shown that sans serif fonts are much easier to read on a computer monitor as opposed to a serif font.
font-family: courier, serif
font-family: arial, "lucida console", sans-serif
<p style="font-family: arial, 'lucida console', sans-serif">
family-name: A prioritized list of font family names and/or generic family names for an element.